2019-20 Southern California rainstorm season
The 2019-20 Southern California rainstorm season is an ongoing event that monitors all rainstorms that affect Southern California. Rainstorms are rated based on how much rain falls in Sand Diego County, excluding the mountain regions. Deaths, damage, wind speed, and pressure are not factors in how storms are rated. Rainstorms ImageSize = width:700 height:230 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:250 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/11/2018 till:30/04/2019 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/11/2018 Colors = id:canvas value:gray(0.88) id:GP value:red id:RD value:rgb(0.38,0.73,1) legend:Rain_Depression_(0.20-0.34) id:WRS value:rgb(0,0.98,0.96) legend:Weak_Rainstorm_(0.35-0.74) id:MRS value:rgb(1,1,0.80) legend:Moderate_Rainstorm_(0.75-1.09) id:SRS value:rgb(1,0.91,0.46) legend:Strong_Rainstorm_(1.10-1.69) id:IRS value:rgb(1,0.76,0.25) legend:Intense_Rainstorm_(1.70-2.49) id:ERS value:rgb(1,0.56,0.13) legend:Extreme_Rainstorm_(2.50-3.29) id:CRS value:rgb(1,0.38,0.38) legend:Catastrophic_Rainstorm_(3.30-4.24) id:ARS value:rgb(0.70,0.01,0.01) legend:Apocalyptic_Rainstorm_(4.25+) Backgroundcolors = canvas:canvas BarData = barset:Hurricane bar:Month PlotData= barset:Hurricane width:11 align:left fontsize:S shift:(4,-4) anchor:till from:19/11/2018 till:21/11/2018 color:ARS text:"Bianca (4.34)" from:27/11/2018 till:29/11/2018 color:CRS text:"David (3.84)" from:03/12/2018 till:04/12/2018 color:SRS text:"Faith (1.69)" from:06/12/2018 till:08/12/2018 color:WRS text:"Hugo (0.71)" from:22/12/2018 till:23/12/2018 color:IRS text:"Jason (2.03)" bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/11/2018 till:01/12/2018 text:November from:01/12/2018 till:31/12/2018 text:December from:01/01/2019 till:31/01/2019 text:January from:01/02/2019 till:28/02/2019 text:February from:01/03/2019 till:31/03/2019 text:March from:01/04/2019 till:30/04/2019 text:April Apocalyptic Rainstorm Bianca (Raymond) Bianca formed as the remnants of Tropical Storm Raymond merged with a cold-core low pressure system moving south. This created ample conditions for heavy rain and thunderstorms. On November 19, a train of storms continued over the area around Escondido and Valley Center, causing over 2 inches of rain. The next day, heavy rain became more widspread. Several downpours moved through the area around La Mesa, and Encinitas was struck by several weak thunderstorms. At 2:30pm, Vista and Carlsbard were struck by a series of heavy thunderstorms, generating strong winds and torrential rain. In the evening, in nearby Oragne County, a funnel cloud was spotted. Showers lingered across San Diego county into November 21, dropping an additional .5 to 1 inches of rain between Valley Center and Alpine. The highest non-mountainous rainfall was in Valley Center, where a whopping 4.34 inches fell. Other significant totals include 3.32 inches in south Escondido, 3.70 inches in Ramona, 3.10 inches in Borrego Springs, and 3.31 inches in Jamul. The SDTWFC in Vista recorded 1.72 inches. In the mountains, which aren't included in the intensity of the storm, 4.70 inches fell at Lake Henshaw, 4.44 inches at Descanso, 4.88 at Palomar Mountain, and 4.72 at Birch Hill. In nearby regions, 4.75 inches fell at the Tijuana International Airport, and 1.90 inches fell at Crestline. In downtown Los Angeles and surrounding areas, pea sized hail was reported on November 20. Strong winds downed trees in El Monte. Bianca also caused significant rainfall across Arizona, causing widspread 2 to 6 inches of rain, especially in the mountains near Phoenix. Rainfall in Arizona peaked at 5.55 inches near Salome. Catastrophic Rainstorm David A very powerful bomb cyclone made landfall in Northern California, sending a potent weatehr system into southern California. On November 29, a band of light to moderate rain moved through Orange and San Diego Counties, resulting in widespread rainfall totals of around a quarter of an inch. In the early morning hours of November 28 - Thanksgiving day - the cold center of the system moved into southern California and mingled with a plume of subtropical moisture pulled in from the Pacific, resulting in numerous strong thunderstorms. At around 8am, a squall line moved into the coast of San Diego County, brining with it torrential rains, isolated hail, and destructive winds. Imbedded within the squall was several waterspouts, including 2 with a visible signature on radar, thought none made landfall. The morning storms ushered in a continous 'river' of moderate to heavy rain. Rain rates in some places reached up to 2 inches per hour, and at one point, 80% of the county was in a flood advisory or flash flood warning. Widespread urban flooding occurred, and rivers and streams across the county overflowed their banks. In the mountains, the snow level plummeted to around 1,800 feet, causing snow to accumulate in the high deserts and mountain passes. Very heavy snow fell at higher elevations, and some places also experienced thundersnow. By the late afternoon, the rain had weakened significantly. However, around 8pm, a second band of intense storms developed offshore and impacted San Diego County, prompting a very rare severe thunderstorm warning to be issued for the central costal region, including Vista, Rancho Santa Fe, and Escondido. The following day, moderate showers lingered into the afternoon, and heavy mountain snow continued. One strong storm caused hail to fall from Bonsall to Warner Springs, and produced thundersnow in Palomar Mountain. Camp Pendleton, CA (November 26, 2019).png| A tornadic signature on radar from the morning squall line Rainstorm David damage (1).jpg| Wind damage from David in Carlsbad Rainstorm David flooding (1).jpg| Flooding in Encinitas from David Rainstorm David flooding (2).jpg| More flooding in Encinitas from David Rainstorm David flooding (3).jpg| A flooded park in Carlsbad Rainstorm David severe thunderstorm warning.jpg| The severe thunderstorm warning issued on November 28 David radar (5).png| radar imagery from the storms that prompted the severe thunderstorm warning In the non-mountainous regions of San Diego County, widspread 2-3.5 inches of rain fell. The highest rainfall total was 3.84 inches near the Sage Hill Preserve in southern Escondido. Other significant rainfall totals include 3.51 inches in San Onofre, 3.01 inches in Oceanside, 3.05 inches in Valley Center, 2.88 inches in Lemon Grove, 2.46 in Mission Valley, 2.69 inches in Encinitas, 2.89 inches in San Marcos, and 2.61 inches in Bonsall. The SDTWFC in Vista recorded 2.71 inches, one of the highest recorded November totals. In the mountains, rain was much less due to the snowfall. Snowfall totals were very significant, and some places recieved so much snow that the snow ranked in the top 5 snowiest November storms. A massive 48 inches fell ar the Big Bear Resort, Snow Valley saw 36 inches, 34 inches in Arrowhead Lake, 24 inches on Mount Baldy, 27 inches in running Springs, 18 inches in Idyllwild and also Mount Laguna, 22 inches in Palomar Mountain, and 28 inches in Wrightwood. In areas below 4,300 feet, snow was less but still significant. Julian (4,200 feet) saw 7 inches, 0.75 inches in Apple Valley (2,700 feet), 4 inches in Phelan (3,600 feet), 2 inches in Victorville (2,600 feet), 3 inches in Yucaipa (3,000 feet), 7 inches in Lytle Creek (3,500 feet), 5 inches in Lancaster (2,400 feet), 4 inches in Anza (3,900 feet), and 3 inches in Palmdale (2,600 feet). Snow accumulations of less than 1 inches fell in the mountain passes, including the Cajon Pass and I-8 pass in San Diego. Trace accumulations also fell in Santa Ysabel, the upper hills of Ramona, Warner Springs, and Calimesa. In the coasts and valleys of nearvy counties, rainfall was generally less but still significant. 3.00 inches fell in Westminster, 2.45 inches in Long Beach, 2.35 inches in Laguna Hills, 2.67 inches in San Clemente, 2.48 inches in Murrieta and also Beaumont, 2.68 inches in Pomona, 4.01 inches in Rancho Cucamonga, 2.89 inches in Arcadia, 2.57 inches in Yorba Linda, and 3.29 inches in Claremont. Most places in Los Angeles County recieved less than 2 inches of rain. Strong Rainstorm Faith A low pressure system tapped into a weak atmospheric river that impacted southern California on December 3 and 4. Late on December 3, scattered showers began to move into Orange and San Diego Counties, dropping generally light rain. In the late morning of December 4, heavier rain moved into Orange Count, developing into a slow-moving blob of moderate to heavy rainfall. At the same time, widspread light and moderate rain developed over San Diego County. By 11am, the rain had become heavier and much more widspread, woth most areas seeing rain rates between 0.25 and 0.45 inches an hour. Small streeam flooding was reported in Escondido. Moderate to heavy rain continued until around 2pm. After that, scattered showers continued. At around 8:30pm, several intense, isolated thunderstorms moved through Vista, Oceanside, and Carlsbad, leading to very hevay rainfall and intense winds. After 10pm, almost all showery activity had ceased. Due to the showery nature of the storm, rainfall was locally higher, thought most places averaged between 0.75 inches and 1 inch. The highest total was 1.69 inches at the SDTWFC in Vista. Other high totals in the non-mountainous areas of San Diego County included 1.52 inches in Valley Center, 1.63 inches in La Mesa, 1.31 inches in Ramona, 1.38 inches in Winter Gardens, and 1.31 inches in Mission Valley. Snow levels stayed mostly above, 7,500 feet, causing rain to accumulate in the mountains. 2.26 inches fell in Boulder Creek, 2.72 feel on Palomar Mountain, 1.52 inches in Julian, 1.99 inches in Otay Mountain, and 1.61 inches on Mount Laguna. In nearby mountains, rain fell in similar amounts, with 1.53 inches in Pine Cove, 1.74 inches on the Santa Rosa Plateau, 2.32 inches in Pine Flats, 1.66 inches in Running Springs, 2.24 inches in Forest Falls, and 1.85 inches at the west end of Big Bear Lake. In the coastale regions of other counties, rainfall was mostly under 1 inch, except for a few isolated locations. 1.50 inches fell in Rancho Cucamonga, 1.26 inches in Covina, 1.15 inches in Pacific Palisades, 1.13 inches in El Monte, Temecula, and Inglewood, and 1.64 inches in Claremont. Weak Rainstorm Hugo On December 6, a weak low pressure system moved into Southern California. The arrival of the storm was accompanied by a large band of moderate rain that moved into the coast of southern California, from Ventura to San Diego. However, by the time the band had reached land, it weakened significantly. Almost all of the storm's rainfall came from this first band. The following days, very spotty showers continued across San Diego County, including a few isolated heavy showers and thunderstorms. One such storm produced a funnel cloud over Hemet. Rainfall was much higher in the mountains. By the evening of December 8, the showers had moved out of southern California. Rainfall was very light across the non-mountainous areas of San Diego County. The highest total was an isolated 0.71 inches in the San Diego County Estates. Other high totals include 0.58 inches in Lemon Grove, 0.60 inches in La Mesa, 0.61 inches in Pala, 0.66 inches in Bonsall, and 0.56 inches in La Presa. The SDTWFC in Vista recorded 0.44 inches. Along the coastal regions of other counties, rainfall was heaviest in San Bernardino and Los Angeles Counties. 0.61 inches fell in Santa Monica, 0.60 inches in Brea, 0.89 inches in Altadena, and 0.69 inches at the Burbank International Airport. In Orange and Riverside Counties, rainfall was significantly less, with almost every station seeing less than 0.35 inches of precipitation. In the mountains, rainfall was heavier. 1.32 inches fell on Mount Cuyamaca, 1.15 inches in Julian, 1.00 inches in the southern Santa Margarita Mountains, and 2.05 inches fell at Palomar Mountain. In the mountains of other counties, 1.77 inches fell in Pine Cove, 1.02 inches fell in Forest Falls, 3.23 inches in Running Springs, 3.32 inches in Valley View Park, 2.06 inches on Mount Disappointment, 2.17 inches along the Angeles Crest Highway, and 2.60 inches in the Santa Paula Canyon. Intense Rainstorm Jason After a 2 week dry period, a low pressure system tapped into an atmospheric river. Early on December 22, a powerful train of heavy rain began impacting Santa Barbara and San Luis Obispo Counties, slowly moving southeast. By the afternoon, the heavy rain had spread into Ventura and Los Angeles Counties, continuing to dump rain at rates up to an inch per hour. However, as the low pressure system moved deeper into California, it began moving the band of heavy rain faster. Late on December 22, the storms moved into Orange County, and particularily heavy rain targetted the Orange/San Diego county line. In the early morning hours of December 23, the band of heavy rain moved into the offshore waters of San DIego County. By 5:45am, the line moved onshore in San Diego County, bringing very heavy rain. However, as it moved inland, it rapidly lost strength. Scattered showers continued through the day on December 23. Due to its initial slow moving nature, rainfall in Orange, Los Angeles, Ventura, and Santa Barbara Counties were much higher than in San Diego County. 2.93 inches fell in Santa Barbara, 1.79 inches in Ventura, 2.26 inches in Port Hueneme, 2.60 inches in Santa Monica, 3.10 in the Palos Verde Hills, 1.57 in Downey, 2.54 in Torrance, and 1.58 inches in Irvine. Rainfall in Orange and San Bernardino Counties was mostly under 0.75 inches. The highest total in the noun-mountainous regions of San Diego County was an isoloated 2.03 inches in San Onofre, just half a mile from the Orange County border. Other high totals included 1.88 inches in the Sage Hill Preserve, 1.75 inches in Torrey Pines, 1.34 inches at the San Diego International Airport, and 1.77 inches at the Brown Field Municipal Airport. Other totals across the county were 1.00 inches in Imperial Beach, 1.14 inches in Lemon Grove, 1.31 inches at the Miramar Executive Airport and Escondido, 1.24 inches in Del Mar, and 1.03 inches in Oceanside. The SDTWFC recorded 0.74 inches. Due to the line of storms weakening as it moved inland, mountainous rainfall totals were much below average compared to other intense rainstorms. 1.37 inches fell at Mount Cuyamaca, 0.91 inches in Julian, 0.95 inches on Palomar Mountain, and just 0.47 inches in Idyllwild. In the San Bernardino, Orange, and Los Angeles County mountains, rainfall was higher. 2.36 inches fell on the Santa Rosa Plateau, 1.71 inches in the San Antonio Canyon, 2.08 inches on Hovt Mountain, 1.54 inches in Lake Arrowhead, 2.29 inches in Mill Creek, 2.61 inches near Brent Mountain, and 2.96 inches near Topanga. Storm Names This SDTWFC uses 4 rotating name lists. Names not retired will be used again in the 2023-24 season. Auxiliary List If the main naming list is exhausted, then the auxillary list will be used.